Compact InAs Quantum Dot Multilayers Realizing High-Power Lasers

Utilizing quantum dots (QDs) as a gain medium to achieve ultra-high optical output at telecommunication wavelengths remains a persistent goal. In this work, we present an approach to enhance optical gain while maintaining a compact active region, suitable for high-power QD lasers operating at a wavelength of 1.31 µm. By reducing the growth temperature of InAs QDs in the latter layers, compact 12-layer QDs with high density and photoluminescence intensity are achieved. Based on this optimized structure, high-power QD lasers are grown and fabricated with a 1600 µm cavity length and a 2.5 µm ridge width, delivering a maximum output power of 212 mW, a peak wall-plug efficiency of 16%, and a maximum net modal gain of 6.6 cm^-1 at room temperature. Moreover, the device demonstrates excellent thermal robustness, maintaining an output power of 99 mW at 110 ℃.